This invention relates to automatic tomato harvesters which include means other than manual labor for separating from the mass of harvested tomatoes culls, that is, tomatoes having undesirable characteristics such as an off color (e.g. green and unripe), rot, or of an insufficient size.
Tomato harvesting is being increasingly automated. For some time now, tomato harvesting machines or combines are in widespread use. U.S. Pat. Nos. 3,193,020; 3,390,768; and 3,437,151 are illustrative of a tomato harvester that is presently extensively used both domestically and abroad. In summary, this as well as other prior art tomato harvesters sever the tomato vines from the ground and deliver the vines and tomatoes attached thereto to a shaker unit where the tomatoes are separated from the vines. The vines are thereafter discharged to the ground and the separated tomatoes are directed to sorting belts, normally located on each side of the harvester and running longitudinally towards an aft end of the harvester. From the sorting belt the tomatoes are discharged to suitable receptacles carried on trucks driven alongside the harvester through the field.
The lateral sorting belts are relatively long and platforms are positioned so that a multitude of workmen can stand on the platforms and screen the tomatoes passing rearwardly along the sorting belts. The primary task of the workmen is to remove from the belts culls, that is rotted, over-ripe or unripe (green) tomatoes as well as foreign objects such as dirt clods or vines. Because of the large volume of tomatoes carried on the sorting belts it is necessary to accommodate between 20 to 30 workmen on the platforms.
It is apparent that the large number of workmen on the harvester is relatively expensive and significantly contributes to the cost of machine harvesting tomatoes. To reduce these costs attempts have in the past been made to automate the separation of culls from the tomato flow. It is presently estimated that within a relatively short time, perhaps as early as the 1976 harvesting season, tomato harvesters will be available on the market that incorporate an automatic sorting system.
Briefly, the contemplated tomato sorting systems employ optical sensors which inspect each tomato, including culls, and which generate a reject signal in response to the presence of a cull. The reject signal is then used to remove the corresponding cull from the tomato flow towards the collection receptacle. The actual removal of the cull from the tomato flow normally employs free-fall trajectories for all tomatoes in which each cull (in response to a reject signal) is deflected from its trajectory as, for example, by applying an air-blast against the free-falling cull or by mechanically pushing the cull from its free-fall trajectory.
Other prior art automatic sorting systems employ a variety of means for removing culls or unacceptable objects from a flow of tomatoes, fruit or objects such as bottles. These methods push the fruit or object sideways, or upwardly and sideways. Illustrative of such prior art are U.S. Pat. Nos. 3,612,274; 3,770,111; and 3,013,661.
Without questioning the efficacy of the known prior art sorters, they are not well adapted for incorporation in the large number of already existing harvesters which rely on manual sorting. The reasons, therefore, are primarily related to the construction of the sorting systems disclosed in the prior art and specifically to their requirement for substantial additional space either sideways of the sorting belt and/or beneath the sorting belts. A lateral expansion of the harvester, however, is frequently not feasible because they are already built as wide as possible while permitting their movement on highways, railroads, and other transportation means. Space beneath the sorting belts of tomato harvesters is normally severely limited and the necessary space to obtain free-fall trajectories of acceptable length and means for finally discharging the culls to the ground is frequently not available.